The invention relates to an apparatus for the separate winding of slit webs onto at least two web rolls supported on support rolls driven in rotation.
For the winding of slit webs onto at least two web rolls, apparatuses based on two different principles are known. In a winding apparatus based on one of these principles and known from German Pat. No. 11 96 463, for example, the web rolls are supported with their axes parallel on two driven support rolls whose axes are parallel to and slightly spaced from each other. Since the web rolls bear with their entire weight on the support rolls, the pressure which they exert on the support rolls increases steadily as the web being wound builds up and becomes heavier. As a result, the outer turns of the roll being wound are subjected to an increasing mechanical load and the density of the roll increases because of the ever more pronounced roll-clearance effect, and ultimately the web may even rupture if the load becomes too great. The roll-clearance effect at two support rolls increases the load on the web still further.
In the second type of apparatus, known from U.S. Pat. No. 3,792,824, for example, two web rolls are arranged in a diametrically opposed relationship on a common support roll, these two web rolls being supported in separate axial bearings and the bearings being displaceable radially relative to the support roll as the web-roll diameter increases. In this apparatus, the weight of the web roll is absorbed by the axial bearing, and the stresses which are due to the weight of the web roll, and which increase with its diameter, act on the center of the web to bring about its rupture. That center must further absorb the horizontal forces, required for the line-contact pressure, which are externally applied by means of pressure cylinders. The vertically acting forces due to the weight and the horizontally acting forces due to the contact pressure add geometrically.